Influence of Fluid Viscosity on the Residence Time Distribution of Micro Reactors Made of LTCC

2008 ◽  
Author(s):  
G. A. Groß ◽  
S. Schneider ◽  
B. Schleif ◽  
J. M. Ko¨hler
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Dispersion Model ◽  
Internal Diameter ◽  
Fluid Viscosity ◽  
Complex Relation ◽  
Micro Flow ◽  
Micro Reactors ◽  
Micro Mixer

The residence time distribution of LTCC microreactors was investigated depending on flow rates and fluid viscosities. A pulse trace experiment was used for monitoring the tracer signals before and behind the microreactors. The tracer signals were measured by use of micro flow-through photometers without disturbing the liquid flow. Therefore, the micro photometers were mounted directly onto FEP tubings. The residence time distribution (RTD) was determined by calculation of the dispersion model using the inlet and outlet tracer profiles. The RTD of a LTCC micro mixer and a LTCC plain meandered channel mixer were determined in the flow rate range between 50 μL/min and 3 000 μL/min using water and aqueous glycerol mixtures up to a glycerol content of 50%. Received data were compared with a PTFE tube (1 mm internal diameter) as reference. A complex relation of determined RTDs between the Reynolds number (Re) and the fluid viscosities was found. A significant non-monotonous effect of the fluid viscosity was observed. The RTD as well as the tailing behavior indicates clearly viscosity-dependent changes in the fluid regime and transport mechanisms.

scholarly journals Investigations Concerning the Residence Time Distribution of Twin-Screw-Extrusion Processes as Indicator for Inherent Mixing

Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 207 ◽  
Author(s):  
Jens Wesholowski ◽  
Andreas Berghaus ◽  
Markus Thommes
Keyword(s):  
Residence Time ◽  
Mass Flow ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Dispersion Model ◽  
Model Parameters ◽  
Twin Screw Extrusion ◽  
Characteristic Model ◽  
Screw Extrusion ◽  
Twin Screw

Over recent years Twin-Screw-Extrusion (TSE) has been established as a platform technology for pharmaceutical manufacturing. Compared to other continuous operation, one of the major benefits of this method is the combination of several unit operations within one apparatus. Several of these are linked to the Residence Time Distribution (RTD), which is typically expressed by the residence time density function. One relevant aspect for pharmaceutical processes is the mixing capacity, which is represented by the width of this distribution. In the frame of this study the influence of the mass flow, the temperature and the screw-barrel clearance were investigated for a constant barrel load (specific feed load, SFL). While the total mass flow as well as the external screw diameter affected the mixing performance, the barrel temperature had no influence for the investigated range. The determined results were additionally evaluated with respect to a fit to the Twin-Dispersion-Model (TDM). This model is based on the superimposition of two mixing functions. The correlations between varied process parameters and the obtained characteristic model parameters proved this general physical view on extrusion.

Residence time distribution in coil and plate micro-reactors

2019 ◽  
Vol 207 ◽  
pp. 181-193
Author(s):  
Alexandra Hopley ◽  
Brendon J. Doyle ◽  
Dominique M. Roberge ◽  
Arturo Macchi
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Micro Reactors

Hydrodynamics of a modified up-flow anaerobic sludge blanket reactor treating organic fraction of municipal solids waste

2020 ◽  
Vol 18 (7) ◽  
Author(s):  
José Vian ◽  
Sergio E. Vigueras-Carmona ◽  
Alejandra Velasco-Perez ◽  
Kelvyn B. Sánchez-Sánchez ◽  
Hector Puebla
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Flow Reactor ◽  
Dispersion Model ◽  
Buffer Zone ◽  
Tracer Test ◽  
Anaerobic Sludge ◽  
Organic Fraction ◽  
Anaerobic Sludge Blanket

AbstractThe hydrodynamic of modified up-flow anaerobic sludge blanket (UASB) treating organic fraction of municipal solids wastes (OFMSW) was investigated using tracer test experiments and residence time distribution (RTD) based models. The modified UASB digester employing the up-flow reactor concept was composed of the sludge bed, localized at the bottom of the reactor, a buffer zone above the sludge bed, a section with the OFMSW, and an upper section with a solid–liquid–gas separator. The solid-state section with the OFMSW allows the separation of hydrolytic and methanogenic phases, reducing the acidification of the reactor. The hydraulic flow transports the faster biodegradable fraction from the packing section to the sludge bed, favoring the methane productivity. Residence time distribution curves were analyzed by three tracer test models (axial dispersion model ADM, tanks in series model TIS and a multiple parameter model MPM). The MPM was successfully fitted to the experimental data.

scholarly journals Kinetic and residence time distribution modelling of tubular electrochemical reactor: analysis of results using Taguchi method

2020 ◽  
Author(s):  
R. Mythilishri ◽  
V. P. Kamalakannan ◽  
R. Saravanathamizhan ◽  
N. Balasubramanian
Keyword(s):  
Taguchi Method ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Dispersion Model ◽  
Supporting Electrolyte ◽  
Chemical Reactor ◽  
Electrochemical Reactor ◽  
Experimental Results ◽  
Axial Dispersion Model

Abstract Decolorization of dye waste water is performed using a Tubular Electrochemical Reactor. Stainless steel and oxide coated on titanium mesh acts as the cathode and anode respectively. Experiments were conducted in batch with recirculation mode. The effect of operating parameters such as current density, initial dye concentration, flow rate and supporting electrolyte concentration on decolorization of Acid red dye has been studied and the results were analysed using Taguchi Method. A Residence Time Distribution (RTD) study has been conducted in a Tubular electro chemical reactor and an axial dispersion model has been developed to determine percentage decolorization. The model results are compared with experimental results and it was found that the model satisfactorily matches with the experimental results with high correlation coefficient.

Analysis Of Residence Time Distribution Of Fluid Flow By Axial Dispersion Model

2010 ◽  
Author(s):  
Sugiharto ◽  
Zaki Su’ud ◽  
Rizal Kurniadi ◽  
Abdul Waris ◽  
Zainal Abidin ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Dispersion Model ◽  
Axial Dispersion ◽  
Axial Dispersion Model

Dispersion Number Studies in ChemicalMechanical Planarization

2003 ◽  
Vol 767 ◽  
Author(s):  
Ara Philipossian ◽  
Erin Mitchell
Keyword(s):  
Fluid Dynamics ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Dispersion Model ◽  
Flow Behavior ◽  
Plug Flow ◽  
Operating Conditions ◽  
The Coefficient Of Friction ◽  
Dispersion Number

AbstractThis study explores aspects of the fluid dynamics of CMP processes. The residence time distribution of slurry under the wafer is experimentally determined and used to calculate the Dispersion Number (Δ) of the fluid in the wafer-pad region based on a dispersion model for non-ideal reactors. Furthermore, lubrication theory is used to explain flow behaviors at various operating conditions. Results indicate that at low wafer pressure and high relative pad-wafer velocity, the slurry exhibits nearly ideal plug flow behavior. As pressure increases and velocity decreases, flow begins to deviate from ideality and the slurry becomes increasingly more mixed beneath the wafer. These phenomena are confirmed to be the result of variable slurry film thicknesses between the pad and the wafer, as measured by changes in the coefficient of friction (COF) in the pad-wafer interface.

Particle Residence Time Distribution of Collection Zone in Packed Flotation Column

2013 ◽  
Vol 781-784 ◽  
pp. 2195-2200
Author(s):  
Li Zhang ◽  
Yi Gang Ding ◽  
Jun Ji ◽  
Chang Yan Yang ◽  
Yuan Xin Wu
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Dispersion Model ◽  
Packed Column ◽  
Flotation Process ◽  
Particle Residence Time ◽  
Flotation Column ◽  
Axial Dispersion Model ◽  
In Series

In order to make a further understanding of flow pattern and back mixing in the flotation process, the study about particle residence time distribution of collection zone in a packed column has been designed. The pulse tracer method was applied and the particle tracers were the mineral gangue in special size class. The residence time distribution curves of our experiment data shows that there are particle back mixings which were caused by fluid flow and geometry factors in the column. The tank-in-series model has a better fitting to the particle residence time distribution in the column according the comparison research between the tank-in-series model and axial dispersion model. The operation parameters have different effects on the particle residence time distribution according to our experimental study.

Model of residence time distribution function in the reactor with dispersion flow and ideal mixing

1980 ◽  
Vol 45 (10) ◽  
pp. 2751-2760
Author(s):  
Jaroslav Košut ◽  
Ján Ilavský ◽  
Martin Dudák
Keyword(s):  
Distribution Function ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Volume Fraction ◽  
Dispersion Model ◽  
Ideal Mixing ◽  
Approximative Solution ◽  
Two Parameters ◽  
Closed Reactor

A function of residence time distribution is derived by the method of generalized Heaviside series and an approximative procedure for the dispersion model coupled with ideal mixing boundary conditions, for "closed-closed" reactor, were used. Model is characterized by two parameters: Peclet number and volume fraction of the region of dispersion flow. The solution is studied numerically and the advantages of the approximative solution are discussed in detail.

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