| 摘要 |
PROBLEM TO BE SOLVED: To reduce noises leaked from a duct consisting of glass-wool boards, and obtain a duct having high mechanical strength. SOLUTION: An inner-outer double cylinder 1 consisting of glass-wool boards comprises an inner cylinder 2 and an outer cylinder 3 which are arranged internally and externally, respectively, with an interval therebetween to form a double structure. A number of parting boards 4 which consist of glass-wool boards, respectively, are juxtaposed between the inner and outer cylinders 2, 3, with a given interval therebetween, so that a number of spaces are formed between the inner and outer cylinders 2, 3, being established by the parting boards 4. When fanned by an air conditioner, noises generated by the air conditioner are mitigated by the inner cylinder 2, and the noises leaked from the inner cylinder 2 are absorbed by the parting boards 4 and the outer cylinder 3, thereby drastically reducing the noises leaked outside the outer cylinder 3. |
