A device (1a . . . 1i) for processing thermoplastic plastic is described, comprising a storage container (2) for receiving pieces of plastic particles or a conveying line (14) for conveying the pieces of plastic particles, and a conveying screw (3) following the storage container (2)/the conveying line (14) at a transfer opening (A). The device (1a . . . 1i) also comprises an extruder (4) following the conveying screw (3) and an air outlet (7) arranged opposite the transfer opening (A) and directed at this opening. A method for operating the device (1a . . . 1i) is also described, in which an air stream is aligned with the transfer opening (A). The strength and/or the direction of the air stream is adjusted or controlled as a function of a load on the extruder (4).