| 摘要 |
The invention relates to a sound attenuator (1) for low frequencies for example for an air-conditioning duct (2) of paper mills, the flow (20), travelling in which duct, can be arranged to pass through the sound attenuator, which sound attenuator comprises a sound attenuator frame (3), which can be arranged in connection with the air-conditioning duct, and which sound attenuator frame comprises a flow duct (4) and, arranged in connection with the sound attenuator frame, at least one attenuator member (5) operating according to the plate resonator principle. The attenuator member comprises a first resonator plate (6), the outer surface of which is arranged to be the inner wall of the flow duct, i.e. along which outer surface the flow is arranged to travel, a framework (7), whereto the first resonator plate is attached by its inner surface, a second plate (9), which is essentially parallel to the first resonator plate. The second plate is attached to the framework by its inner surface, whereby the second plate, the framework and the first resonator plate delimit at least one attenuator unit (10). The first resonator plate, attached to the framework, is a steel plate, the first resonator plate is attached to the framework by laser welding and the framework comprises a pressure balancing opening (11). The invention further relates to a method for manufacturing a sound attenuator (1) for low frequencies, and a system for attenuating low frequencies for example in air-conditioning ducts (2) of paper mills. |
