Micro-mechanics of wet solids in gas-solid contactors

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In this project, we will investigate the dynamic behaviour of gas-particle processes involving liquid injection. These systems are encountered in a wide variety of gas-solid contacting processes used in the chemical, pharmaceutical and food industries. It is well known that wet particles behave completely different from dry particles. Yet, a fundamental description of the dynamics of wet particles is predominantly missing. Two PhD students will mutually work on a quantitative description of wet particle dynamics through a combined experimental and numerical study. The first will work on development and application of collision experiments to perform a systematic parameter study of particle collisional behaviour depending on particle material properties, wettability, degree of wetting, impact velocity and physical properties. Two high speed cameras will be used to quantify the changes in velocity and the sticking of particles during a collision. The effects will be analysed due to solving of force and energy balances. The other PhD student will numerically study the mechanisms of particle collisions with the aid of an advanced computational model that describes the dynamics of a particle colliding with a wet wall or another dry or wet particle without any prior assumptions. Based on the experimental and numerical data we will be able to identify the mechanisms of energy dissipation, sticking and transfer of mass and momentum during a collision of a wet particle and to provide quantitatively descriptive closure equations that can be used in coarse grained DEM models. These can be used in the design, optimization and trouble shooting of gas-solid contactors involving liquid injection.