scholarly journals Regression model for fluid flow in a static mixer

2016 ◽  
Vol 18 (1) ◽  
pp. 23 ◽  
Author(s):  
Rajamanickam Akila ◽  
Kumar Balu

<p>A regression model for simulating residence time distribution (RTD) of turbulent flows in helical static mixers is proposed and developed to predict the residence time distribution in static mixers. An efficient method is required to estimate the RTD and the sole means of achieving this is through detailed regression model. The RTD was calculated numerically by regression model. The results of the regression model, i.e. predicted RTD is presented in terms of different volumetric flow rate to illustrate the complicated flow patterns that drive the mixing process in helical static mixers. The regression model is found to fit the experimental RTD with a high degree of correlation.</p><p>Chemical Engineering Research Bulletin 18(2015) 23-29</p>

1964 ◽  
Vol 17 (8) ◽  
pp. 821 ◽  
Author(s):  
RCL Bosworth ◽  
CM Groden

When a reacting substance or mixture is caused to flow in a cylindrical reactor, all portions of the stream will not flow at the same rate and will exhibit different residence times and, accordingly, are subject to different extents of degrees of reaction. The average degrees of reaction following the residence time distribution proper to laminar flow are given in the earlier publication1 and this paper extends the treatment to that of turbulent flow. In the earlier treatment of laminar flow the ratio of average extent of reaction with non-interacting streams to that of complete intermingling, or the C/Cm, is plotted against the ratio of the times of flow with those of reaction (S). The C/Cm versus S curves are all above unity and increase with increasing S, with the exception of very high orders of chemical reaction for which values of C/Cm are all unity. In the case of turbulent flow the values of C/Cm are more nearly unity at all values of S.


2017 ◽  
Vol 19 ◽  
pp. 111
Author(s):  
HW Yussof ◽  
SS Bahri ◽  
AN Phan ◽  
AP Harvey

<p>A recent development in oscillatory baffled reactor technology is down-scaling the reactor, so that it can be used for the applications such as small-scale continuous production of bioethanol. A mesoscale oscillatory baffled reactor (MOBR) with central baffle system was developed and fabricated at mesoscales (typically 5 mm diameter). This present work aims to analyse the mixing conditions inside the MOBR by evaluating the residence time distribution (RTD) against the dynamic parameters of net flow Reynolds number (<em>Re</em><em><sub>n</sub></em>) at 4.2, 8.4 and 12.6 corresponding to flow rates of 1.0, 2.0 and 3.0 ml/min respectively, oscillatory Reynolds number (<em>Re</em><em><sub>o</sub></em>) between 62 to 622, and Strouhal number (<em>Str</em>) between 0.1 to 1.59. The effect of oscillation frequency and amplitude on RTD performance were studied at frequency, amplitude, and velocity ratio ranging from 4 to 8 Hz, 1 to 4 mm and 1 to 118, respectively. Effect of oscillation frequency has resulted in the variance of the RTD increased as the oscillation frequency increased from 5 Hz to 8 Hz and peak at 6 Hz of 0.264. A further increase in the frequency above 5 Hz caused the RTD to slightly broaden and positively skewed. At frequency of 5 Hz, the RTD profiles were close to Gaussian form for all tested amplitude values from 1 mm to 4 mm. At low amplitudes, i.e. xo = 1 mm, the variance exhibited its minimum around 0.842 at <em>Re</em><em><sub>o</sub></em><em> </em>=156. An increase in <em>Re</em><em><sub>o</sub></em><em> </em>above 300 resulted in increased in the variance rapidly to 1.28, and later eliminated the plug flow behaviour and the reactor behaved similar to a single continuous stirred tank reactor.</p><p>Chemical Engineering Research Bulletin 19(2017) 111-117</p>


AIChE Journal ◽  
2009 ◽  
Vol 55 (1) ◽  
pp. 279-283 ◽  
Author(s):  
Cai-Liang Zhang ◽  
Lian-Fang Feng ◽  
Sandrine Hoppe ◽  
Guo-Hua Hu

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