Development of experimental design and image processing methods for drops diameter measurement in an annular centrifugal solvent extraction contactor (ECRAN) - Archive ouverte HAL Access content directly
Conference Papers Year : 2016

## Development of experimental design and image processing methods for drops diameter measurement in an annular centrifugal solvent extraction contactor (ECRAN)

#### Abstract

Liquid-liquid extraction is a well-known method used to separate compounds based on their relative solubilities in two different immiscible liquids. Among the different types of liquid-liquid extraction apparatus, centrifugal extractors have advantages of low liquid hold-up and high mass transfer efficiency. As a consequence, many types of industrial monostage or multistage centrifugal extractors are currently used in nuclear but also pharmaceutical, food, chemical or hydrometallurgy industries with capacities from a few liters per hour to 100 cubic meters per hour. In order to determine these industrial applications, testing must generally be performed on small scale equipment to evaluate liquid-liquid extraction relevant parameters such as drop size distribution which is the objective of this investigation. Among the miniature extraction contactors developed since 1970, CEA has conceived a new annular centrifugal contactor referred as ECRAN with two original properties : • there are two rotors driven by the same shaft and positioned the one under the second; the upper accomplishes the separation of the phases, the lower the mixture • the two phases are fed at the bottom of the mixing zone by means of two channels and discharge into the separation rotor after mixing ; so the emulsion fills the entire mixing zone and its volume is constant at any experimental conditions. The CEA chose the ECRAN to measure the drop size distribution of liquid/liquid systems with the shear rate which depends on the rotor speed and the gap in the annular mixing zone. Images have been processed using three different image analysis software : ImageJ, Matlab and DaVis. In order to ensure best possible drop detection, every processing technique has involved several steps : crop, denoising, background removal, thresholding, contour detection, particle analysis. Results are presented by histograms of the drop diameter and descriptive statistics (mean diameter,…). The number of detected drops by the three image processing methods is generally different ; despite these differences, the deviation of the mean diameters in a same test calculated by the three techniques is of around $\pm$20 per cent.

### Dates and versions

cea-02439466 , version 1 (26-02-2020)

### Identifiers

• HAL Id : cea-02439466 , version 1

### Cite

P. Rivalier, J-L. Bourrier, F. Lamadie, M. de Lorenzi. Development of experimental design and image processing methods for drops diameter measurement in an annular centrifugal solvent extraction contactor (ECRAN). Atoms For the Future 2016 - "Time in nuclear energy », Jun 2016, Paris, France. ⟨cea-02439466⟩

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