Abstract: An in-duct cleaning apparatus characterized by comprising a traveling truck, an ejection nozzle body for ejecting compressed air, a cleaning brush body, and a remote-control portion; the ejection nozzle body being attached to the front part of the traveling truck and made to rotate, the cleaning brush body being attached to the circumferential part of the ejection nozzle body, and the remote-control portion being able to control remotely the traveling of the traveling truck and the rotation of the ejection nozzle body.

Abstract: A system including an apparatus for cleaning an inside surface of a duct. The system includes a traveling portion and a remote-control monitor portion. The traveling portion includes a traveling truck and the truck carries a compressed air ejector and a video camera, and the remote-control monitor portion receives images from the video camera to control remotely the traveling portion while monitoring a front view of the traveling portion in accordance with the signal coming from the video camera. The compressed air ejector is equipped with a rotating nozzle for ejecting compressed air toward the duct inside surface in an oblique direction in front of the traveling truck. An air compressor can be carried by the truck or the compressed air can be fed to the nozzle ejector via a hose from outside the duct.

Abstract: An in-duct searching apparatus characterized by comprising a traveling truck, a video camera for in-duct observation on board the traveling truck, a singular or plural compressed air ejecting nozzle, and a monitor/remote-control portion for remotely controlling the traveling truck and the video camera and the compressed air ejecting nozzle; wherein the compressed air ejecting nozzle ejects compressed air toward the alien substances inside the duct which have been observed by the video camera, for grasping their properties.