The soundproof elbow is an elbow lined with sound-absorbing material, which has a significant attenuation effect on sound waves. Sound attenuation consists of three parts: absorption and reflection of near axial waves on the curved wall, and the conversion of near axial wave energy into oblique wave energy during turning, which is effectively absorbed by sound-absorbing materials.
The soundproof elbow is an elbow lined with sound-absorbing material, which has a significant attenuation effect on sound waves. Sound attenuation consists of three parts: absorption and reflection of near axial waves on the curved wall, and the conversion of near axial wave energy into oblique wave energy during turning, which is effectively absorbed by sound-absorbing materials. Inserting a right angled sound-absorbing elbow into a rectangular cross-section tube and adding sound-absorbing pads on both sides of the elbow, with a length of 2 to 4 lz (where lz is the characteristic width of the tube cross-section), results in a high-frequency insertion loss that is 10 dB higher than that of a straight tube with the same length of pads. The so-called high frequency refers to the frequency higher than the cut-off frequency of the pipeline. The function of the silencing elbow at low frequencies is similar to that of a liner straight pipe of the same length, without additional insertion loss.