HEAT TRANSFER TUBE FOR LNG VAPORIZER, ITS PRODUCTION METHOD, AND LNG VAPORIZER USING SUCH HEAT TRANSFER TUBES

摘要

The present invention discloses a heat transfer tube (heat transfer tube) for LNG vaporizer to prevent effectively that the surface is heavily cooled damaged by corrosion of the surface of the Al alloy substrate even when used to the bottom or the lower header of a hard panel to oxide film formation do. ; Such heat transfer tube is used for an LNG vaporizer Al alloy panel unit is provided comprising a panel, and a bottom header and a top header respectively connected to the lower end and upper end of the panel made up of a plurality of heat transfer tubes arranged in a curtain shape, wherein LNG is flowing down from the upper end of the unit panel along the surface of the panel is vaporized by heat exchange between the LNG flowing in the sea water and the heat transfer tube. In such LNG vaporizer, crude by blasting at least the outer surface and the outer surface of the lower headers of the heat transfer tube in the lower end of the panel, the cotton was then, a Mg content in the range of 1 to 80% by mass and a thickness of 100 to 1000㎛ by a coating of Al-Mg alloy having formed by the thermal spray implements a victim way. Scheme layer as Zn and / or Mn of 0.3 to contain a content of 3.0% by mass (the content of the stage, (Zn + Mn) is in the range of 0.3 to 3.0% by mass), and Mg in 0.3 to 5 mass% of the content of forming an alloy film containing Al be also effective.