Silencer with frequency separating and modulating baffle

Claim 1

A silencer adapted to reduce the combined noise level of a flow medium and working mechanism normally above 90 decibels to a sum total value below 90 decibels comprising: a housing having an inlet for passage of said flow medium into said housing and an outlet; opposed dome shaped porous first and second noise reducing members with their open ends in abutting relation, forming a chamber in between them; said first noise reducing member having surfaces disposed adjacent said inlet for passage of said flow medium into said chamber, and said second noise reducing member having surfaces extending from the housing outlet defining an outlet for passage of said flow medium from said chamber to atmosphere, so that the noise level of said flow medium as it passes through said first and second noise reducing members is substantially reduced, and a porous frequency separating and modulating baffle disposed between said first and second dome shaped members within said chamber, having an annular flange retained between abutting outer portions of said dome shaped members, and inwardly of said flange irregularly shaped contoured portions extending into at least one of said dome shaped members and having a total surface area greater than the maximum cross sectional area between said dome shaped members for reducing and modifying high pressure frequencies and reducing back pressure.