Measurement of Wetting Efficiency in Packed Tower Using Stimulus Response Technique.

Packed towers are used in many unit operations such as absorption, extraction, distillation, humidification and hydrotreating reactors. Liquid flows down the packed bed by gravity over the packing elements to create gas-liquid / liquid-solid contact area for mass transfer across the phases. Ratio of gas-liquid area to surface area of packing element is known as effective interfacial area; ratio of liquid solid contact area to surface area of packing elements is known as wetting efficiency. Efficiency of a packed tower depends on the wetting efficiency of packing elements. Many researchers investigated wetting efficiency in packed towers. Yet there is still no reliable scientific basis to accurately estimate wetting efficiency. In this investigation, available literature information on wetting efficiency in a packed tower is reviewed and experimentally measured using stimulus response technique of pulse input at three different flow rates using RTD Studies in Packed Bed equipment. The result obtained is compared with other literature data. Through experimental data simple model for estimating wetting efficiency is developed. However further refinement of equation is needed for better accuracy. The data are analysed through a rivulet flow model.