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Flow Reactor - Modeling and Simulation

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Flow Reactor Modeling and Simulation - Model the fluid mixing characteristics of large scale storage vessels with the interactive Residence Time Distribution Curve Simulator.


















Perfectly Mixed Flow:
In a Perfectly Mixed Flow reactor there are no spatial gradients of temperature or of material concentration. A perfectly mixed flow reactor may be modellized by an exponential decay curve as indicated.

Non Ideal Flow:
In a real fluid mixing reactor the flow may inlude zones such as: i) flow re-circulation, ii) Stagnant flow or dead volume and iii) flow short circuiting. Non ideally mixed flow can be modellized by RTD curves.

Residence Time Distribution Curves:
RTD curves involve the injection of a conservative tracer to the inlet stream of a fluid mixing reactor. RTD curves may be used to fit a reactor model that describes the real flow characteristics of the fluid mixing vessel.

             
Input: Tank Volume
C0 - Initial Concentration
1.00
Input: Tank Flow Rate
T - Nominal Residence Time
200.10
1/T
0.0050
 
 
 
 



For example, a tank may be described as a re-circulating flow reactor with 10% dead volume. Subsequent design modification and reactor model analysis may lead to the elimination/reduction of unmixed zones thereby leading to a more efficient mixing process.

Re-Circulating Flow:
Within a re-circulating flow reactor non-uniform dispersion of the incoming particles, and both chemical and turbulent diffusion will take place leading to an imperfectly mixed tank. A single non-ideal tank may be modelled as a number of (n) smaller ideally mixed reactors in series with flow re-circulation.

Plug Flow: The output response from an ideal Plug Flow vessel will be identical to that of the input stimulus. If a unit pulse of tracer were injected into a vessel in which dispersion and diffusion do not take place, then after a time delay equivalent to the Nominal Residence Time (T) of the vessel, a unit pulse response would be recorded at the outlet stream.

Residence Time Distribution: For ideal plug flow within a vessel all fluid elements will spend the same amount of time in the system. Non ideal flow through a container will have a distribution of residence times.