SOUND-ABSORBING RING STRUCTURE Russian patent published in 2017 - IPC G10K11/168 E04B1/84 

FIELD: physics.

SUBSTANCE: sound-absorbing element made in the form of external and internal perforated walls, between which a sound absorber is placed consisting of three layers of sound-absorbing material, wherein the first layer, more rigid, is made solid and profiled and is fixed to the outer surface, the second layer, softer than the first one, is made discontinuous and is located in the focus of the sound-reflecting surfaces of the first layer, wherein the first layer, the more rigid one, is made solid and profiled, and the second layer, softer than the first one, is made discontinuous and is located in the focus of the sound-reflecting surfaces of the first layer, and the third layer of the sound-absorbing element is made of foam sound-absorbing material, for example a construction sealing foam, and is located between the first, more rigid layer and the perforated surface of the sound-absorbing element, the discontinuous sound-absorbing layer located in the focus of the solid profiled layer, is made in the form of rotation bodies, for example in the form of balls, rotation ellipsoids and is fastened by means of rods, parallel to the perforated surfaces which are rigidly connected to each other by means of vertical fastening elements, perpendicular to them, for example in the form of plates, one end of which is rigidly fixed to a smooth surface, and the second is made in the form of a clamp which surrounds the rod and a compression screw.

EFFECT: increased efficiency of noise absorption at low and medium frequencies.

2 cl, 1 dwg