| 20080216911 | Integrated spiral duct - Provided is an integrated spiral duct including: a curved duct; and straight connection ducts formed at both ends of the curved duct, wherein the curved duct is integrally formed with the straight connection ducts in spiral type without any joint. Therefore, since a metal strip is continuously wound to form a duct without any joint, it is possible to reduce the number of manufacturing processes to remarkably increase productivity, quality, and durability. | 09-11-2008 |
