In Travelling Bed Gas Adsorber, freshly regenerated adsorbent is elevated and added at the top of the column at a rate to maintain a constant height of solids.
A mechanism is provided at the bottom for the steady removal of saturated sorbent which is regenerated in another vessel before being returned to the top.
Gas enters at the bottom and passes up the column being purified and leaving at the top. In travelling bed units, the bed rests on a bottom support grill or grate and the gas passes upwards through the voids in the granular bed of solids.
In the tray design, solids are fluidized on each tray by the gas rising through sieve-plate holes in the tray.
The solids slowly travel across the tray to a down comer which conducts the solids to the tray below so that the design resembles that of a plate-type adsorption column.