Silencer for perforated plate flow conditioner

A perforated plate flow conditioner comprising:

• a. a central hole and a plurality of surrounding holes;
• b. a downstream side;
• c. a single hollow acoustic feedback interference device having an upstream end and a downstream end, the upstream end attached to the downstream side;
• wherein the upstream end covers substantially all of the space between the central hole and all of the surrounding holes on the downstream side, but does not cover any holes, and wherein the acoustic feedback interference device is selected from the group consisting of solid cones, solid cylinders, and solid rectangular beams.

A perforated plate flow conditioner comprising:

• a. a plurality of holes;
• b. a downstream side;
• c. hollow acoustic feedback interference devices having upstream ends and downstream ends, the upstream end of each device attached to the downstream side;
• wherein each upstream end covers substantially all of the spaces between adjacent holes on the downstream side, but does not cover any holes, and wherein the acoustic feedback interference device is selected from the group consisting of solid cones, solid cylinders, and solid rectangular beams.