Abstract: An apparatus for cleaning the interior sidewall of a large diameter tube includes a centrally-apertured circular brush plate adapted to fit within a lumen of the tube. A fluid conduit is mounted in the aperture so that an upper part of the fluid conduit is positioned above a plane of the circular brush plate and a lower part is positioned below the plane. A nozzle assembly is disposed in radial relation to the lower part of the fluid conduit. A hose provides fluid communication between a remote source of water under pressure and the fluid conduit. The circular brush plate is inserted into the lumen of the tube and is gradually advanced through the tube. The nozzle assembly is rotated about an axis defined by the fluid conduit as the circular brush plate is advanced through the tube so that water under pressure cleans the interior sidewall of the tube.

Abstract: Residual concrete in the drum of a ready mixed concrete truck is removed by high-pressure water. A nozzle is mounted on the leading end of a torpedo-shaped nozzle housing that is hingedly mounted to an elongate boom. The boom enters the mouth of the drum at an angle that matches the angle of the drum. The hinge allows the nozzle housing to pivot with respect to the elongate boom so that the nozzle is close to the residual concrete. The boom is retracted toward the mouth with the drum rotating in the mix direction and the nozzle oscillating so that it cuts through a swath of concrete. As the boom retracts, the torpedo-shaped nozzle housing maintains the nozzle close to the residual concrete on the drum and both sides of the helical fins. The nozzle sweeps an arc from about eighty to one hundred twenty degrees as it oscillates.