Influence of Oslo crystallizer structure characteristics on crystallization process
Abstract
The liquid–solid multiphase flow in Oslo crystallizer was simulated by computational fluid dynamics (CFD) and described by Euler–Euler model and k-ε turbulence model. The velocity field and solid phase concentration field in Oslo crystallizer with different structural elements were systematically studied. The results show that, within the range of 0–82.5°, the fluid velocity and axial mixing in the evaporation chamber are significantly affected by the inlet pipe structure, and the length of the central downcomer also has distinct impact on the crystal classification ability of the crystallizer. As the angle between the axis of the inlet pipe and the tangent line at the inlet point increases, the tangential velocity in the evaporation chamber decreases, the axial velocity near the wall increases, and the volume fraction of solid particles decreases. As the length of the central downcomer increases, the position of the vortex center gradually goes up and moves towards the wall. In order to obtain high-quality products and extend the continuous operation cycle of the device, the angle between the axis of the inlet pipe and the tangent line at the inlet point should be 60–75°, and the distance between the central downcomer and the bottom of the crystallizer should be .8 m.
