US Patent 7195034 Fluid trim apparatus and method

A noise reducing apparatus and method for handling of fluid comprises a plurality of discs stacked on one another, each disc having a radially inner periphery and a radially outer periphery, and a plurality of fluid flow channels defined on at least some of the discs and extending from the inner periphery to the outer periphery. One or more sound reducing material elements are disposed to extend across at least some of the fluid flow channels so that fluid flowing through the channel passes through the sound absorbing material. Alternatively, a plurality of sound absorbing wafers are disposed in between adjacent discs and form a respective wall of the flow channels with respect to the flow channel of an adjacent disc.