Tray efficiency measures the performance of a distillation tray or trays against the maximum theoretical performance. Similarly, a concept called Height Equivalent to Theoretical Plate (HETP) is used to measure the performance in a packed column. This article describes methods of quantifying tray efficiency in distillation tray analysis.
As fluid flows through a packed bed it experiences a pressure loss due to friction. This article describes the use of the Carman-Kozeny and Ergun equations for the calculation of pressure drop through a randomly packed bed of spheres.
The packed bed Reynolds number is dimensionless and describes the ratio of inertial to viscous forces for fluid flow through a packed bed. It may be used to calculate the pressure drop though a packed bed via the Ergun equation or identify the boundaries of flow regimes (laminar, transitional and turbulent) in a packed bed. This article will show you how to calculate and interpret the packed bed Reynolds number.