96 / | HD | GAS SEPARATION: APPARATUS |
424 | DF | WITH TIMING OR CHANGEABLE PROGRAMMING MEANS {2} |
425 | .~ Of cleaning mechanism for separating media {2} | |
426 | DF | .~.~> Sequential cleaning of plural separating media {1} |
428 | DF | .~.~> For control of pneumatic reverse flushing |