96 / | HD | GAS SEPARATION: APPARATUS |
15 | DF | ELECTRIC FIELD SEPARATION APPARATUS (E.G., ELECTRICAL PRECIPITATOR, ELECTROSTATIC TYPE, ETC.) {17} |
55 | DF | .~ And serially arranged nonelectrical separator {3} |
57 | DF | .~.~ Precedent nonelectrical separator {1} |
58 | .~.~.~ Separator is single porous filter |