Poor drainage can cause liquid holdup, pressure-drop increase, re-entrainment, fouling, and separator flooding. Drainage capacity depends on separator geometry, orientation, liquid loading, supports, fouling condition, and cleaning arrangement.

Demister bypass, re-entrainment, and excessive upstream entrainment can all cause downstream liquid carryover. Their load behavior, pressure-drop pattern, installation condition, and process history help distinguish one mechanism from another.

Re-entrainment occurs when liquid already captured by a mist eliminator is stripped from the separator and carried downstream again. High gas load, excessive liquid loading, fouling, poor drainage, and local flow concentration can all contribute. Troubleshooting should therefore evaluate drainage and hydraulic stability—not only initial droplet capture.

Geometric surface area in m²/m³ describes the macroscopic walls or struts of ceramic media, while BET surface area in m²/g describes microscopic porous surface accessible to gas adsorption. The two numbers cannot be directly compared and serve different roles in catalyst design.

Ceramic grid packing module size should balance manufacturing, manway access, handling, support geometry and joint control. Smaller blocks fit vessels more easily but create more interfaces, so total joint area and perimeter bypass must be considered in the layout.