scholarly journals Nucleation in continuous flow cooling sonocrystallization for coiled capillary crystallizers

2021 ◽  
Author(s):  
Mira Schmalenberg ◽  
Lena K. Weick ◽  
Norbert Kockmann
Keyword(s):  
Time Distribution ◽  
Residence Time Distribution ◽  
Flow Cell ◽  
Deionized Water ◽  
Small Scale ◽  
Non Invasive ◽  
Ultrasonic Bath ◽  
Continuous Crystallization ◽  
Wide Range ◽  
Inner Diameter

AbstractNucleation in continuously operated capillary coiled cooling crystallizers is experimentally investigated under the influence of ultrasound. It was found that there is no sharp boundary but rather a transition zone for nucleation under sonication. For this purpose, a tube with an inner diameter of 1.6 mm and a length of 6 m was winded in a coiled flow inverter (CFI) design and immersed into a cooled ultrasonic bath (37 kHz). The CFI design was chosen for improved radial mixing and narrow residence time distribution, which is also investigated. Amino acid l-alanine dissolved in deionized water is employed in a supersaturation range of 1.10 to 1.46 under quiet and sonicated conditions. Nucleation is non-invasive detected using a flow cell equipped with a microscope and camera. Graphical abstract Since the interest and demand for small-scale, continuous crystallization increases, seed crystals were generated in a coiled tube via sonication and optically investigated and characterized. No distinct threshold for nucleation could be determined in a wide range of supersaturations of l-alanine in water

Flow and residence time distribution in small-scale dual-layer depth filter capsules

2021 ◽  
Vol 617 ◽  
pp. 118625 ◽  
Author(s):  
Minyoung Kim ◽  
Negin Nejatishahidein ◽  
Ehsan Espah Borujeni ◽  
David J. Roush ◽  
Andrew L. Zydney ◽  
...  
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Small Scale ◽  
Layer Depth

scholarly journals Effect of oscillation amplitude on the residence time distribution for the mesoscale oscillatory baffled reactor

2017 ◽  
Vol 19 ◽  
pp. 111
Author(s):  
HW Yussof ◽  
SS Bahri ◽  
AN Phan ◽  
AP Harvey
Keyword(s):  
Reynolds Number ◽  
Residence Time ◽  
Oscillation Frequency ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Chemical Engineering ◽  
Continuous Production ◽  
Velocity Ratio ◽  
Small Scale ◽  
Gaussian Form

<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>

Temperature-Controlled Minichannel Flow-Cell for Non-Invasive Particle Measurements in Solid-Liquid Flow

2020 ◽  
Author(s):  
Mira Schmalenberg ◽  
Fabian Sallamon ◽  
Christian Haas ◽  
Norbert Kockmann
Keyword(s):  
Crystal Size ◽  
Evaluation Method ◽  
Quality Criterion ◽  
Flow Cell ◽  
Small Scale ◽  
Two Phase ◽  
Non Invasive ◽  
Temperature Controlled ◽  
Controlled Flow ◽  
Solid Liquid

Abstract Solid-liquid suspension flow is often involved in the production of pharmaceuticals and fine chemicals. In these fields, working with continuous small-scale equipment in order to save costs and resources is of increasing interest. Therefore, it is also important to enable process control for small-scale apparatus, which requires the development of new concepts to observe and control crystallization processes in minichannel equipment. The particles and crystals should be detected and measured with as low impact as possible because contact between process medium and the sensors can often lead to the incrustation of the sensor, disturb the particle size and shape, or contaminate the system. For the observation of crystallizing processes in minichannel crystallizers, a non-invasive, temperature-controlled flow-cell is designed in this work. In particular, this flow cell has been designed to examine crystals in a fluorinated ethylene propylene (FEP) tube with an inner diameter of 1.6 mm. Crystals can be investigated using a standard optical camera and microscope. An image processing routine enables the evaluation of crystal size. This is crucial for the assessment of the process and crystal size distribution, which is often a quality criterion in the crystallization process. The contribution will show how the flow-cell for two-phase flow is constructed and the evaluation routine is implemented. Based on experimental data, the applicability of the equipment and the evaluation method are described.

Residence time distribution study for the catalytic packing MULTIPAK®

2006 ◽  
Vol 60 (6) ◽  
Author(s):  
A. Górak ◽  
M. Jaroszyński ◽  
A. Kołodziej
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Reynolds Numbers ◽  
Axial Dispersion ◽  
Dispersion Coefficients ◽  
Column Operation ◽  
Distribution Study ◽  
Inner Diameter ◽  
Very High

AbstractResidence time distribution (RTD) experiments were carried out using the catalytic packing MULTIPAK® in a 250 mm inner diameter column. The axial dispersion coefficients and dynamic liquid hold-up were derived from the RTD curves. Both hold-up and axial Péclet number were correlated in terms of gas and liquid Reynolds numbers. Free-draining experiments were performed to determine the dynamic and static liquid hold-ups.The measured axial dispersion coefficients were higher than those presented in other studies. The dynamic hold-up derived from RTD agreed with total hold-up from free-draining experiments. The static hold-up was found very high, even higher than the dynamic one, due to the liquid accumulated inside the catalyst bed. Possibly, the liquid considered “static” from the viewpoint of the free-draining experiments becomes “dynamic” during the normal column operation.

Role of Cardiac MRI in Detecting Familial Hypertrophic Cardiomyopathy: Review

2016 ◽  
Vol 1 (1) ◽  
pp. 4
Author(s):  
Marymol Koshy ◽  
Bushra Johari ◽  
Mohd Farhan Hamdan ◽  
Mohammad Hanafiah
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Magnetic Resonance ◽  
Genetic Disorder ◽  
Familial Hypertrophic Cardiomyopathy ◽  
Non Invasive ◽  
Wide Range ◽  
Proper Diagnosis ◽  
Magnetic Resonance Imaging Mri ◽  
Potential Use

Hypertrophic cardiomyopathy (HCM) is a global disease affecting people of various ethnic origins and both genders. HCM is a genetic disorder with a wide range of symptoms, including the catastrophic presentation of sudden cardiac death. Proper diagnosis and treatment of this disorder can relieve symptoms and prolong life. Non-invasive imaging is essential in diagnosing HCM. We present a review to deliberate the potential use of cardiac magnetic resonance (CMR) imaging in HCM assessment and also identify the risk factors entailed with risk stratification of HCM based on Magnetic Resonance Imaging (MRI).

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