METHOD OF FORMING, INSERTING AND PERMANENTLY BONDING RIBS IN BOILER TUBES.

摘要

A method of providing boiler tubes with a variably ribbed interior surface. A suitably dimensioned spindle with a channel having a desired pattern on the exterior surface of the spindle is wrapped by a wire-like member in the channel so as to form thereon a reverse image of the desired, patterned tube ribbing. A brazing metal paste is applied on the exterior surface of the wire-like member and the spindle is inserted into a tube to be ribbed. The wire-like member is released from the spindle to allow the wire-like member to conform to the inner surface of the tube, and the tube is heated to the melting temperature of the brazing metal paste so that the wire-like member bonds to the inner surface of the tube, and the metal tube is then cooled.