REGENERABLE FILTER SYSTEM CONTAINING FOUR FILTER BEDS

摘要

A regenerable filter system (10) includes a flow path (40) along which a stream of fluid flows between an inlet (42) and an outlet (44). A first filtering unit (20) is located in the flow path. The first filter unit includes first and second regenerable filter beds (A, B), wherein each bed h as a first adsorbent for removing a first contaminant from the fluid stream. A first valve (V1) is located between the inlet and the first filtering unit f or selectively directing the fluid stream through one of the first and the seco nd filter beds. The other of the first and second filter beds is removed from t he flow path. A second filtering unit (30) is located in the flow path between the first filtering unit and the outlet. The second filtering unit includes third and fourth regenerable filter beds (C, D) for removing a second contaminant from the stream of fluid. A second valve (V2) is located between the first filtering unit and the second filtering unit for selectively directing the stream of fluid through one of the third and fourth filter bed s, wherein the other of the third and fourth filter beds is removed from the fl ow path. A controller (76) operates the first valve (V1) such that the stream o f fluid is directed through one of the first and second filter beds. The secon d valve (V2) is so operated that the stream of fluid is directed through one o f the third and fourth filter beds. The first and second filtering units are operated independent of one another.