HEATING TUBE FOR BOILERS AND METHOD OF MANUFACTURING THE SAME

摘要

In order to control the precipitation and formation of a deposition produced in an inner face portion of a heat transmitting tube for a boiler due to a boiler water and the formation of an oxide scale of a tube material due to over-heated steam, there is provided a heat transmitting tube for a boiler provided with a porous sprayed coating formed by using a metal.alloy having excellent high temperature oxidation resistance and corrosion resistance at high temperature as compared with a material of the heat transmitting tube onto an outer heat receiving surface contacting with a combustion gas, and an oxide ceramic, and an oxide cermet, in which solid inorganic sintered fine particles are penetrated and filled in opening pores of the porous sprayed coating and form a covering layer on the surface of the coating and solidified at a high melting point to produce a heat shielding function to thereby prevent an excessively heat flow to the heat transmitting tube. <IMAGE>