Abstract: A scrubber for blast furnace gas has a primary purifying unit and a secondary purifying and pressure adjusting unit in series with the primary unit. The primary purifying unit includes venturi having a divergent-constant diameter-convergent core in which the gas experiences a pressure loss and is subjected to a first washing with water. The secondary purifying unit comprises a multi-stage venturi including a first stage having a constant-diameter annular passage, followed by a diffuser section and at least one adjustable stage in series with the first stage which defines an annular passage of variable size.