| 摘要 |
PURPOSE:To prevent heat transmitting tubes from being damaged, by flame- spraying metallic powder to the surfaces of heat transmitting tubes which are supported by baffle plates. CONSTITUTION:A heat transmitting tube 10 is preliminarily treated so as to be ready to be flame-sprayed, by hardening the surface of the tube 10 by means of shot blasting or sandblasting, and by defatting using trichlene. Then, the mixed powder, consisting of less than 94wt% of titanium dioxide, oxide powder of 4- 8wt% of aluminum, and 2-6wt% of vanadium, and nickel and chrome alloy powder consisting of 12-18wt% of chrome, 5-9wt% of iron, and nickel for the remainder wt%, is flame-sprayed to the surface of a heat transmitting tube. In this case, less than 1mm. is enough for the thickness of a layer to be flame- sprayed, but for fear that a little number of pin holes will be formed in the flame-sprayed layer, it is necessary to fuse the part by heating it with flames immediately after flame-spraying. |
