Abstract: Movable means are provided interiorly of a rotating confined line on a substantially horizontal plane through which reactant fluids, such as liquids and gases, flow and react, whereby inherently to inhibit the adherence of particulate matter within the line and effect enhanced contact and intermingling of the liquid maintained in the form of a pool therein with the gas during rotation of the line.The movable means comprise relatively solid objects which bounce and tumble within the line to contact the interior of the line. The relatively solid objects, which may be in the form of chains, wires, cables or any other solid media whether consisting of separate or joined components, also function to prevent the liquid, maintained in the pool and/or passing through the line from assuming a dry or precipitate state as it is splashed or otherwise distributed about the entire interior periphery of the line.