Hold-down grids, or bed limiters, are situated directly over a packed bed to prevent the movement or discharge of the packing. They are particularly necessary in such cases where packing can experience uplift due to high gas loading or sporadic pressure surges. Additionally they can be used to separate packing of different sizes to avoid intermixing within the column.
|Types||Materials of construction|
|Expanded metal||M 100 S||-||-|
|Flat||M 100||P 100||K 100|
Other types or special designs
The units are designed so that they do not disturb the steady state of the liquid distribution.
Depending on the model, hold-down grids either sit directly on the top of the packed bed or they are mechanically attached to the vessel wall. It is also possible to hang them directly from the liquid distributor or re-distributor. Additionally they can be integrated into the design of the liquid distributor or re-distributor.