Patent ID: 6622818
Filing Date: 2003-09-23
Classification: F01N,F16L,F24F,Y10S

Abstract:
A sound attenuating device for use in a gas transportation duct, said device comprising a core of acoustically absorptive material substantially enclosed within an impervious film to prevent direct contact between the acoustically absorptive material and gas flowing through said gas transportation duct, said enclosed absorptive material being maintained in position between at least two perforated facing plates wherein there is provided between the perforated facing and the impervious film, spacing means to prevent contact between the film and the perforated facing and blocking means to impede the internal flow of air between the film and the perforated facing and wherein there is further provided between the impervious film and the acoustically absorptive material, spacing means to prevent contact between the film and the acoustically absorptive material and blocking means to impede the internal flow of gas between the film and the acoustically absorptive material and as a complete assembly to allow unrestricted movement of the impervious film in a void between the acoustically absorptive material and the perforated facing.