Numerical Investigation of Pressure Drop in Single Pellet String Reactors

In narrow fixed-bed reactors the influence of the confining wall on pressure drop cannot be neglected. Here, the pressure drop in single pellet string reactors, a limiting case of fixed-bed reactors with a cylinder-to-particle diameter ratio below 2, is studied using computational fluid dynamics simulations. Deviations to the Ergun, and more specifically Blake-Kozeny equation are evident though the general trend is met. A geometry-based weighting factor is introduced to scale the influence of the confining wall in an equivalent diameter expression. Agreement between numerical simulation and pressure drop predictions from correlation are thereby improved significantly.