(114d) CFD Simulation and Experimental Investigation of a Fractal Fluid Distributor

Uniform  flow distribution is critical for many unit operations in  chemical engineering as it often defines hydrodynamics in process vessels. Flow maldistribution is also  the major factor affecting equipment scale-up.   Design of conventional fluid distributors is typically based on pressure drop with non-equivalent hydraulic pathways leading to different outlets.  Fluid distributors based on fractal geometry that are based  on pathway symmetry rather than pressure drop offer precise control of fluid properties. Fractal-based distributors have been used in the industry for the last 20 years, especially in the processes with granulated media. Although the flow behavior in the fractals is well understood, the interaction of specific design features and flow patterns within the resin bed needs to be additionally studied. A  fractal distributor with one inlet and 256 outlets has been  studied for  an ion-exchange device (one distributor, resin bed, collector). Results of CFD modeling and experiments of residence time distribution will be presented.  The influences of flow rate, resin depth, flow orientation, and outlet density, are investigated. CFD Simulation of this ion-exchange device has been performed  with ANSYS WORKBENCH. Key evaluation parameters include COV (coefficient of variation) and pressure drop. Three different fluid distributors with different channel cross-section area have been tested and the result shows with higher flow rate, the COV increases and the middle sized distributor has the lowest COV.