The invention relates to a device (1a..1i) for processing thermoplastic plastic which comprises a storage container (2) for receiving pieces of plastic particles or a conveying line (14) for conveyingthe pieces of plastic particles, and to a conveying screw (3) connected to the storage container (2)/the conveying line (14) at a transfer opening (A). The device (1a..1i) also has an extruder (4) which connects to the conveying screw (3), and an air outlet (7) situated opposite the transfer opening (A) and directed at this opening. The invention also relates to a method for operating the device(1a..1i) in which an air stream is aligned with the transfer opening (A). The strength and/or the direction of the air stream is controlled depending on a load level of the extruder (4).