Reference : UPR3346-NADMAA-073
Workplace : ANGOULEME
Date of publication : Friday, September 23, 2022
Type of Contract : FTC Scientist
Contract Period : 6 months
Expected date of employment : 1 November 2022
Proportion of work : Full time
Remuneration : Between 2805 € et 3963 € gross monthly according to experience
Desired level of education : PhD
Experience required : Indifferent
At the CNRS, on the Angoulème site, the Pprime Laboratory is recruiting a Researcher/Post-doc to participate in the research activities of the Tribo-electrostatic team relating to the contract of the PPRIME Institute with the MICHELIN company: research and development of a method for electrostatic separation of titre wear debris founf in two ore mixtures.
The collaboration contract between the two institutions is part of the continuity of the research and development activities carried out by the "Tribo-electrostatic" team of the PPRIME Institute on the site of the IUT of Angoulême. It aims to study the feasibility of electrostatic separation of tire wear debris in two ternary mixtures of ORES MT1 (wear debris + chalk + silica) and MT2 (wear debris + chalk + alumina). The work will initially consist of identifying the appropriate method of electric charging of each of the four materials separately and of the two mixtures. Each material and the two mixtures will then be subjected to the action of an electric field, possibly combined with mechanical forces, to assess the feasibility of electrostatic separation of the ternary mixtures MT1 and MT2:
* Step 1. Study of the state of the art (1 /11– 1/12/ 2022)
The bibliographic synthesis on the physical mechanisms of electric charging of tyre wear debris, chalk, silica and alumina separately and ternary mixtures MT1 and MT2 should allow the analysis of their possibilities of use for the sorting of tyre wear debris.
* Step 2. Evaluation of the electric charging (16 /11 – 31 /12/ 2022)
Tests will be carried out on tribocharging devices available at the IUT of Angoulême and for which receptacles of three or four different materials will be made to establish triboelectric mini-series of the four materials of the MT1 and MT2 mixtures. The evaluation of the efficiency of electric charging by electrical corona discharge will also be conducted for the four materials of the MT1 and MT2 mixtures. This test campaign on the behavior of each of the four materials of the MT1 and MT2 mixtures will aim to identify the charge mechanisms to be implemented to control the electrostatic behavior of the MT1 and MT2 mixtures.
* Step 3. Evaluation of the electrostatic separation of the granular mixtures (01/01/– 30/04/2023)
The identification of the charge mechanisms of each of the four materials of the MT1 and MT2 mixtures will make it possible to develop strategies for their electrostatic separation. Tests will be carried out on a multifunction conveyor belt separator. Several high voltage values and the two polarities will be tested to study the feasibility of separating tire wear debris from MT1 and MT2 mixtures. If the results of these separations were to prove satisfactory, solutions for the evolution/ adaptation of an electrostatic separator already operational or even the architecture of a new electrostatic separator dedicated to these two mixtures would be proposed.
A study report recording the conditions of the experiments and the results will be drawn up. It will eventually contain the first tracks of evolution or adaptation of an electrostatic separator or even architecture of a new electrostatic separator and will specify the technical specifications necessary for operation
The researcher should have the following skills:
- High voltage engineering
- Instrumentation for measuring electrical quantities (potential, charge)
- Design of experiments methodology
- Data acquisition & analysis techniques
- Writing technical and scientific reports
The CNRS (National Center for Scientific Research) is a multidisciplinary public research body, placed under the supervision of the Ministry of Higher Education, Research and Innovation.
The Pprime Institute is a CNRS UPR (Proper Research Unit) in the fields of Physical and Engineering Sciences. Its activities cover a broad scientific spectrum, from the physics of materials to the mechanics of fluids, solids, mechanical engineering and energy.
The Electro-Fluido-Dynamics team has internationally recognized skills in the experimental and numerical modeling of physical phenomena associated with the movements of charged or polarized particles in a fluid in the presence of an electric field. This ranges from electrostatic precipitation at the scale of nanometer particles to electrostatic separation of granules at the millimeter scale, including electrostatic manipulation of powders and powdery materials at the micrometer scale. The investigation approach is mainly experimental, but it is supported by a growing activity of numerical and analytical modelling. The most important part of this team's activities concerns the research and development of a range of triboelectric chargers (rotating cylinder, fluidized bed, vibration) and electrostatic separators (drum, metal strip, two-disc electrodes) for the recycling of granular materials from waste electrical and electronic equipment. These industrial or laboratory facilities are the result of strong industrial partnerships with the CITF company (two CIFRE theses), manufacturer of special machines, Michelin, APR2 and Environnement Recycling, recycling specialists, as well as university collaborations (PHC – TASSILI and BRANCUSI, ERASMUS) with higher education institutions in Algeria (Sidi-Bel-Abbes, Oran, Guelma, Constantine) or Romania (Cluj-Napoca, Bucharest, Timisoara).
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