Abstract: Device for drying a bundle of threads between a stretching trough and a sizing trough has a tiered array of elongate nozzle bodies each having a plurality of thread channels therein for receiving a partial bundle of threads therethrough. Each channel has a cross section consisting of a semicircular bottom part of radius r and a rectangular top part of width 2r and height r, the semicircular bottom part having a centered air inlet for generating turbulence to dry the threads. The channels are closed by a metal cover which is received flushly against a cover contact surface having an air checking borehole which assures that the cover is in place. A preferred embodiment has channels with restricted inlet and outlet parts to facilitate generating knots of turbulent air in a central turbulent part of the channel.