| 摘要 |
PURPOSE:To contrive to reduce the cost and at the same time enable to keep the airtightness by a method wherein iron or stainless steel is employed to a connecting pipe to connect the outer peripheral part of an absorber pipe with the peripheral edge part of the opening of an end plate and cheaper brazing materials, the melting temperatures of which are different from one another, are employed at joining parts. CONSTITUTION:A first connecting pipe 9' made of iron or stainless steel, the melting temperature of either one of which is higher than that of copper, and a second copper connecting pipe 9'' are employed. At the same time, the brazing between the peripheral edge part 5a of the opening of an end plate 5 and the one end side of the connecting pipe 9' is done by copper brazing metal instead of conventional silver brazing metal. The brazing between the other end side of the connecting pipe 9' and the one end side of the connecting pipe 9'' is done by bronze brazing metal. The brazing between the other end side of the connecting pipe 9'' and the outer peripheral part of an absorber pipe 3 is done by phosphor copper or copper brazing metal with low silver content. Stainless steel, the thermal expansion coefficient of which is nearly equal to that of glass is used in the end plate 5 instead of 42-6 alloy. Because the melting temperatures of solders indescending order of height are of copper brazing metal, bronze brazing metal and phosphor copper brazing metal or copper brazing metal with low silver content, said brazings done by the solders with the melting temperatures lower than that of copper solder do not melt the brazed part between the connecting pipe 9' and the peripheral edge part 5a of the opening of the end plate 5 and consequently do not impair the airtightness of said brazed part.
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