Cleaning of gases using two or more sorption filter beds in series - when predetermined loading of first filter bed is reached, sorption material in first bed is renewed and gas flow is reversed

摘要

A new procedure for improving the performance of sorption materials in absorbing contaminants from gases uses two or more filter beds containing granular sorption materials. The novel feature is that (a) the raw gas stream is led through the first filter bed (I) and the second filter bed (II) until a certain degree of contaminant loading of the absorption material in the first bed is reached, (b) the absorption material is removed from the first bed, (c) the first bed is re-filled with fresh unused or regenerated material (12), (d) the gas stream is reversed and passes through the second filter bed (II) and then the first (I) until a certain degree of loading of the absorption material in the second bed is reached, (e) the absorption material is removed from the second bed, (f) the second bed is refilled with fresh unused material (12) and (g) the gas stream is reversed and the above steps are repeated. Pref. the spaces upstream of the filter beds which remain filled with raw gas are preferably flushed by a stream of clean gas before steps (d) and (g) above - i.e. before each reversal of the gas flow direction. USE/ADVANTAGE - In the cleaning of gas streams. The advantages of multi-path filters in which the filter material travels downwards through a vertical filter vessel - i.e. high rates of absorption material loading, and of multi-layer filters - i.e. compactness of construction are combined.