EXTERNAL WALL CLEANER FOR TUBULAR STRUCTURE

摘要

The invention comprises a cage mountable on a pipe line and bearing a carriage movable on the cage around the pipe line. The carriage supports an elongate arm to lie in the longitudinal direction of the pipe and has a jet cleaning head reciprocable along the arm to clean the exterior of the pipe line. The cage has driven rollers thereon to drive the cage along the pipe line; and an indexing mechanism is provided to step the carriage around the pipe line.