| 摘要 |
The invention provides a fin structure, and a method and apparatus for forming a fin structure, for application to the exterior of a tube to form a heat transfer device effective in minimizing frost bridging in refrigeration operations. The fin structure is wound helically onto a refrigerant-carrying tube, and comprises an integrally formed chain of looped fins, each looped fin having a mounting flange at each end thereof and comprising two vertical fin portions extending respectively from each mounting flange and connected together by a bridge portion; the method and apparatus for making the same includes a unitary stretch preforming process to reform thin lanced sheet metal fin stock into the final looped fin shape in a single forming step. |
