Device for continuously humidifying and dehumidifying feed air

An apparatus for continuously humidifying and dehumidifying feed air for a manufacturing process or a ventilation and air conditioning installation, the apparatus comprising:

• a membrane contactor including a membrane configured to have the feed air passed along one side of the membrane and a hygroscopic liquid passed along another side of the membrane;
• a metering device configured to add water so as to increase the water content of the hygroscopic liquid, the metering device and the membrane contactor being connected in a first circuit for the hygroscopic liquid;
• a regenerator configured to lower a water content of the hygroscopic liquid, the regenerator being connected in a second circuit for the hygroscopic liquid;
• a control device connected to the metering device and to the regenerator, the control device being configured to control the water content of the hygroscopic liquid so as to enable a switching between humidification and dehumidification of the feed air as a function of a water vapor partial pressure difference between the feed air and the hygroscopic liquid;
• at least one first feed line configured to branch off a first partial stream from the hygroscopic liquid in the first circuit and feed the first partial stream into the second circuit;
• at least one second feed line configured to branch off a second partial stream from the hygroscopic liquid in the second circuit and return the second partial stream to the first circuit;
• and
• a heat exchanger, the at least one first feed line and the at least one second feed line passing through the heat exchanger.