| 摘要 |
1514584 Silencing axial-flow fans SASAKURA ENG CO Ltd 27 Oct 1975 [5 Nov 1974] 44185/75 Headings FIB and F1C A noise-absorbing casing ring 1 dimensional to surround the blades 3 of an axial-flow fan comprises a hollow structure having inner and outer circumferential walls 6, 8 enclosing sound-absorbing material 7 (such as glass wool, rock wool, steel wool or nylon or other synthetic fibre), loss of the material through numerous small bores 5 being prevented by a porous protective layer 16. The layer 16 may be of glass cloth, synthetic fibre net or metallic net or may be of stainless steel wool (which additionally acts as a sound absorber). |
