Device for removing dust from the interior of preforms of thermoplastic material by injecting dust removal gas which comprises: - a carousel which is rotatably mounted about a central rotation axis on a fixed base, the carousel comprising retention members for preforms; - injection tubes, each one of which is mounted in a sliding manner on the carousel in correspondence with each retention member between an extreme retracted position and an extreme inserted position inside a preform which is intended to be carried by the associated retention member; - at least one pneumatic actuator which is for controlling at least one injection tube between the two extreme positions thereof and which is controlled automatically in accordance with the angular position of the carousel, the pneumatic actuator comprising at least a first working chamber for controlling the injection tube to move into a first of the extreme positions thereof; characterized in that the dust removal device comprises a rotating fluid distributor which comprises: - an internal stator which is fixedly mounted relative to the base and which comprises a pressure line which is connected to a working gas source and at least one exhaust line; - an external rotor which is rotatably mounted about the stator coaxially relative to the center axis in a manner fixedly joined to the carousel and which comprises at least a first activation aperture which is connected to the first working chamber, the activation aperture travelling a circular trajectory around the center axis; - a first control stage which is connected to the first working chamber of the actuator, comprising: -- a pressure chamber (70B-1) which is interposed radially between the stator and the rotor and which is connected to the pressure line, the activation aperture opening in the pressure chamber (70B-1) over at least a first angular sector of the circular trajectory thereof, referred to as the "angular activation sector (112B-IN)"; -- an exhaust chamber (70B-2) which is interposed radially between the stator and the rotor and which is connected to the exhaust line, the activation aperture opening in the exhaust chamber (70B-2) over at least a second angular sector of the circular trajectory thereof, referred to as the "angular exhaust sector (112B-OUT)"; -- radial walls for separating the pressure chamber (70B-1) and the exhaust chamber (70B-2). - a carousel which is rotatably mounted about a central rotation axis on a fixed base, the carousel comprising retention members for preforms; - injection tubes, each one of which is mounted in a sliding manner on the carousel in correspondence with each retention member between an extreme retracted position and an extreme inserted position inside a preform which is intended to be carried by the associated retention member; - at least one pneumatic actuator which is for controlling at least one injection tube between the two extreme positions thereof and which is controlled automatically in accordance with the angular position of the carousel, the pneumatic actuator comprising at least a first working chamber for controlling the injection tube to move into a first of the extreme positions thereof; - an internal stator which is fixedly mounted relative to the base and which comprises a pressure line which is connected to a working gas source and at least one exhaust line; - an external rotor which is rotatably mounted about the stator coaxially relative to the center axis in a manner fixedly joined to the carousel and which comprises at least a first activation aperture which is connected to the first working chamber, the activation aperture travelling a circular trajectory around the center axis; - a first control stage which is connected to the first working chamber of the actuator, comprising: -- a pressure chamber (70B-1) which is interposed radially between the stator and the rotor and which is connected to the pressure line, the activation aperture opening in the pressure chamber (70B-1) over at least a first angular sector of the circular trajectory thereof, referred to as the "angular activation sector (112B-IN)"; -- an exhaust chamber (70B-2) which is interposed radially between the stator and the rotor and which is connected to the exhaust line, the activation aperture opening in the exhaust chamber (70B-2) over at least a second angular sector of the circular trajectory thereof, referred to as the "angular exhaust sector (112B-OUT)"; -- radial walls for separating the pressure chamber (70B-1) and the exhaust chamber (70B-2). -- a pressure chamber (70B-1) which is interposed radially between the stator and the rotor and which is connected to the pressure line, the activation aperture opening in the pressure chamber (70B-1) over at least a first angular sector of the circular trajectory thereof, referred to as the "angular activation sector (112B-IN)"; -- an exhaust chamber (70B-2) which is interposed radially between the stator and the rotor and which is connected to the exhaust line, the activation aperture opening in the exhaust chamber (70B-2) over at least a second angular sector of the circular trajectory thereof, referred to as the "angular exhaust sector (112B-OUT)"; -- radial walls for separating the pressure chamber (70B-1) and the exhaust chamber (70B-2).