| 摘要 |
A cleaning nozzle for a device for cleaning ducts has a rear part (1) which can be connected to a pressure-medium source, and a front part (2) which is rotatably mounted on the rear part (1). The nozzle contains a turbine imparting to the front part (2) its rotary motion when pressure medium is supplied to the nozzle. A brush (7) and a friction means (5) are detachably mounted on the front part of the nozzle. In use, the nozzle moves in a helical motion on the inner wall of a duct. The front part (2) rotates about its own axis in such a manner that the relative velocity between the front part (2) and the wall in the contact point therebetween is different from zero. The rotating brush (7) efficiently cleans the inner wall of the duct. If the nozzle loses its grip on the wall, the rotation of the rotating part (2) increases to an idling speed, the friction means (5) expanding such that its diameter becomes greater than that of the brush (7), thus enabling the nozzle to regain its grip on the wall. |
