LJUDDAEMPAD ANORDNING, FOERETRAEDESVIS VAEDRINGSDON.

摘要

The sound damper, partic. a ventilator, uses interference or absorption-damping for low, medium or high frequency noise. The damper comprises a housing with passages enclosed by partitions running between an inlet and an outlet. In succession, the passages have linings of material which absorbs medium and high frequency noise in a primary section. A secondary section follows directly on the primary one and operates on the low-frequency interference-damping principle, independently of the passage length in the primary section.