Hollow-fiber membrane assembly and device comprising at least one hollow-fiber membrane assembly

There are a hollow fiber membrane assembly (14) of a device (10) and a device (10) for the transport of substances between two fractions, in particular for the separation of substances from gaseous or liquid streams, particularly for the separation of fluids, in particular for humidifying or dehumidifying the gas (38), described in particular for a fuel cell assembly. The hollow fiber membrane assembly (14) comprises at least one hollow fiber membrane (20), whose wall partially permeable structures and their ends (18) are fixed to / at least one holding medium (16). Several subsequently flowed through the hollow fiber membrane sections (24) of the at least one hollow fiber membrane (20) extending spatially adjacent.