Rapid Determination of the Residence Time Distribution (RTD) Function in an Oscillatory Baffled Reactor (OBR) Using a Design of Experiments (DoE) Approach

2014 ◽  
Vol 12 (1) ◽  
pp. 575-586 ◽  
Author(s):  
Matthew Stanley Richard Abbott ◽  
Adam P. Harvey ◽  
Michelle I. Morrison
Keyword(s):  
Design Of Experiments ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Rapid Determination ◽  
Velocity Ratio ◽  
Plug Flow ◽  
Continuous Processes ◽  
Flow Components

Abstract Residence time distribution (RTD) profiles were investigated in a standard oscillatory baffled reactor (OBR) as a function of oscillatory and bulk flow components using a design of experiments (DoE) approach. A second-order, polynomial model (R2=92.1%) was fitted to N values estimated from concentration profiles and used to maximise plug flow conditions. The velocity ratio (Ψ) required to maximise plug flow was 1.9, agreeing well with the range previously identified by Stonestreet and van der Veeken (1.8 < Ψ < 2.0), suggesting that the approach used here is valid. This method could be used to rapidly quantify and maximise plug flow in various OBR designs in a simple and robust manner which could prove valuable for the operation and design of continuous processes using OBR technology.

scholarly journals Modeling Residence Time Distribution (RTD) Behavior in a Packed-Bed Electrochemical Reactor (PBER)

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Sananth H. Menon ◽  
G. Madhu ◽  
Jojo Mathew
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Flow Model ◽  
Plug Flow ◽  
Flow Characteristics ◽  
Theoretical Models ◽  
Packed Bed ◽  
Electrochemical Reactor ◽  
Tracer Studies

This paper focuses on understanding the electrolyte flow characteristics in a typical packed-bed electrochemical reactor using Residence Time Distribution (RTD) studies. RTD behavior was critically analyzed using tracer studies at various flow rates, initially under nonelectrolyzing conditions. Validation of these results using available theoretical models was carried out. Significant disparity in RTD curves under electrolyzing conditions was examined and details are recorded. Finally, a suitable mathematical model (Modified Dispersed Plug Flow Model (MDPFM)) was developed for validating these results under electrolyzing conditions.

scholarly journals Explicit Residence Time Distribution of a Generalised Cascade of Continuous Stirred Tank Reactors for a Description of Short Recirculation Time (Bypassing)

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 615 ◽  
Author(s):  
Peter Toson ◽  
Pankaj Doshi ◽  
Dalibor Jajcevic
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Flow Reactor ◽  
Plug Flow ◽  
Stirred Tank ◽  
Stirred Tank Reactors ◽  
Delayed Impulse ◽  
In Series ◽  
Back Mixing

The tanks-in-series model (TIS) is a popular model to describe the residence time distribution (RTD) of non-ideal continuously stirred tank reactors (CSTRs) with limited back-mixing. In this work, the TIS model was generalised to a cascade of n CSTRs with non-integer non-negative n. The resulting model describes non-ideal back-mixing with n > 1. However, the most interesting feature of the n-CSTR model is the ability to describe short recirculation times (bypassing) with n < 1 without the need of complex reactor networks. The n-CSTR model is the only model that connects the three fundamental RTDs occurring in reactor modelling by variation of a single shape parameter n: The unit impulse at n→0, the exponential RTD of an ideal CSTR at n = 1, and the delayed impulse of an ideal plug flow reactor at n→∞. The n-CSTR model can be used as a stand-alone model or as part of a reactor network. The bypassing material fraction for the regime n < 1 was analysed. Finally, a Fourier analysis of the n-CSTR was performed to predict the ability of a unit operation to filter out upstream fluctuations and to model the response to upstream set point changes.

Quantitative Analysis of Residence Time Distribution in Kenics Static Mixer

2012 ◽  
Vol 499 ◽  
pp. 198-202 ◽  
Author(s):  
Dan Jin ◽  
Hai Ling Fu ◽  
Jian Hua Wu ◽  
Dan Sun
Keyword(s):  
Quantitative Analysis ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Plug Flow ◽  
Axial Direction ◽  
Static Mixer ◽  
Mixing Quality ◽  
Experimental Approaches ◽  
The Mean

The residence time distribution in Kenics static mixer is investigated using experimental approaches. Experimentally, RTD measure in SK with pulse tracer technology was used to characterize flow and mixing quality. The effect of velocity on the RTD was investigated for all sections. The results show that the flow in SK mixer tends to the plug flow along the axial direction when the velocity increases. The quantization analysis, the effect of factors on the mean residence time, is done by using the power function considering the numbers of mixer element, diameter, element aspect radio, and velocity. The validity of this function is testified by other experiments.

The Mixing Characteristics and Residence Time Distribution of Cut Tobacco Particles in Drum Mixer

2011 ◽  
Vol 396-398 ◽  
pp. 297-301
Author(s):  
Wen Kui Zhu ◽  
Dong Liu ◽  
Jin Song Du
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Plug Flow ◽  
Processing System ◽  
Rotating Speed ◽  
Drum Mixer ◽  
Method Effects ◽  
Residence Time Distributions ◽  
Cut Tobacco

Residence time distributions were determined for the continuous processing of cut tobacco in the rotary drum by introducing expanded cut tobacco tracers to the inlet of the processing system using the negative step change method. Effects of rotating speed of the rotary cylinder and solids flow rate on the mixing homogenization and residence time distribution (RTD) of experiment materials was investigated. PER-CSTR series model and multistage CSTR model were used to fit the experimental results. The result shows mixing homogenization increased significantly with the increasing feeding rate of cut tobacco and decreasing drum rotating speed. PER-CSTR series model is more suitable to describe the RTD characteristics of flow materials in drum. The axis movement of cut tobacco along the drum is approximate to the plug-flow.

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