Patent ID: 8794712

Claim:
A method of removal of refractory material lining the inside of a cylindrical structure by hydro-demolition, said refractory having a surface facing and exposed to an inside cavity of said structure, the method comprising the steps of: providing an apparatus comprising: a traveler adapted to being received within the structure and to being moved continuously along the inside of the structure, the traveler including a securing assembly that secures the traveler within the structure in a manner that allows the traveler to be intentionally moved by an operator; one or more engagement members extending from said traveler for contacting said surface to maintain a central axis of said traveler substantially coincident with a central axis of said structure during travel along the inside of said structure; a rotatable nozzle assembly defining an axis of rotation and being connected to the traveler, the nozzle assembly comprising one or more nozzle lines each terminating in a nozzle head that rotates about the axis of rotation, the nozzle assembly being configured in a manner that each nozzle head is suitably spaced from the refractory to be able to deliver a jet of fluid under pressure to the refractory; a nozzle rotation means for rotating the nozzle assembly; and a conduit means in fluid communication with the nozzle assembly suitable for delivering a flow of fluid to the nozzle assembly under high pressure to disintegrate said refractory material lining the structure; placing the apparatus in the structure so that the axis of rotation of the nozzle assembly is approximately coincident with the central axis defined by the structure; applying fluid at a high pressure to the nozzle assembly through the conduit means whereby high pressure jets of the fluid are forced against said facing surface of said refractory through the nozzle heads; moving the traveler over the entirety of said facing surface of the refractory in order to disintegrate the entirety of said surface and said refractory with the high pressure jets; and providing an extension at a terminal end of the structure wherein the extension is adapted to permit the one or more engagement members to travel along said extension even after the traveler has been moved out of the structure, so as to maintain said central axis of said traveler substantially coincident with said central axis of said structure to enable the refractory material to be removed up to the terminal end of the structure.