Bed Limiters (metal)
For structured packing, bed limiters are recommended to prevent packing displacement when there is the potential for upset conditions. Structured packing columns that operate at a low pressure drop with a low percentage of flood and are not prone to sudden vapor surges typically do not require a bed limiter. For random packing, a bed limiter or anti-migration device is always recommended because conditions that result in the fluidization of some or all packing at the top of a random packed bed are difficult to predict. The anti-migration component can be integral to the liquid distributor or a separate bed limiter can be provided as needed.