Abstract: A coupling and switching unit for transporting a gas-containing fluid includes at least one line having at least one coupling device. The at least one line is configured as a feed line for a gas/liquid mixture. A branched-off line is arranged at the end of the at least one line. The branched-off line is configured to direct the liquid/gas mixture towards an outflow. A throttle valve is arranged in the branched-off line. A valve is configured to control a discharge of a main flow of the gas/liquid mixture.

Abstract: An apparatus for introducing a gas into a liquid in a flow tube includes at least one feed line for the liquid to be gassified and the gas to be introduced, at least one outflow line for a gas/liquid mixture, at least one return line for the gas/liquid mixture, and at least one chamber comprising at least one gas supply device arranged in the at least one return line. The apparatus does not include an injector operating on a Venturi principle.